code: def tag(image_name: str, tag: str) -> Optional[str]:
      """Tag an image."""
      return shell(["tag", image_name, tag])
  
imports: import json
  import logging
  import os
  import subprocess
  from typing import Any, Dict, List, Optional, Tuple, Union
  import requests
  from dockerpycreds.utils import find_executable
  from wandb.docker import auth, www_authenticate
  from wandb.errors import Error
label_desc: Use image node_id 18 for calling a global function with example usage: tag(image_name, tag) and returns: shell